JULY 10-11, 1862.- Expedition to Guntown, Miss.

Report of Captain Robert O. Selfridge, U. S. Army, Assistant Adjutant-General, Cavalry Division, Army of the Mississippi.

HDQRS. CAV. DIV., ARMY OF THE MISS., July 12, 1862.

GENERAL: I have the honor to submit the following report of an expedition with a flag of truce to Guntown, Miss., by Colonel P. H. Sheridan, Second Michigan Cavalry, and myself:

Leaving Colonel Sheridan's camp, between Rienzi and Booneville, at 4 o'clock on the morning of the 10th instant, we proceeded by the Jacinto road to Booneville; there in a southwesterly direction, via Crockett's and Tate's, on the Carrollville road. Learning at Tate's of a picket being stationed at Carrollwille we turned eastward for 2 miles, thence southward for 2 miles farther, to Baldwyn. Learning at this place of a picket on the right-hand road quite near to Baldwyn we turned off to the eastward across the railroad, and proceeded in a southeastwardly direction, intending to pass to the eastward of Guntown and strike Tupelo from the Fulton road; but the absence of water and the suffering condition of our animals precluded this idea, and we were reluctantly compelled to turn back to Guntown after striking the Fulton road 1 or 2 miles south of that place.

In the village of Guntown we found the first picket of the enemy, who received us most cordially, and by whom we were provided with an excellent camp for our escort and most hospitable quarters for ourselves at the house of a Mr. Thomas. On the morning of the 11th we were waited upon by Cols. J. Wheeler and Tracy, of the Nineteenth Alabama; Captain Lenoir, of General Bragg's staff, and Captain Robertson, of the artillery, who received our dispatches, and with whom we exchanged newspapers and discussed in the most friendly manner the various topics of the day, from which we gathered:

First, that their main force is now at and near Tupelo and numbers from 70,000 to 75,000 strong. Second, that the army, since the evacuation of Corinth, has been thoroughly reorganized, and is now under the sole command of General Bragg. Third, that General Beauregard is in disgrace, and is charged with the loss of victory at Shiloh and with want of success at Corinth. Fourth, that no movement is contemplated by them until the maturing and gathering of the present corn crop. Fifth, that when they do advance it will be upon our right flank and as far to the westward as Holly Springs.

We returned, by a circuitous route, through Carrollville and Blackland, leaving Baldwyn and Booneville to the right, and reached camp at midnight on the 11th.

The country, after leaving Twenty Mile Creek, is entirely destitute of water, and even this stream is rapidly failing, and will be entirely dry in two weeks. The roughness of the country about Booneville becomes still more rough and rugged beyond Baldwyn, the hills even in many places approaching the mountainous, covered by a vegetation so dense as to completely cover the ground. The character of the country precludes the passage of troops, unless at vast labor and expense. We found none of the enemy's pickets after passing 2 miles north of Guntown.

I am, general, very respectfully, your obedient servant,
R. O. SELFRIDGE,

Captain and Assistant Adjutant-General Cavalry Division.

Brigadier General W. L. ELLIOTT,

Chief of Staff, Army of the Miss.